A Common ∼55 GeV Inelastic Dark Matter Origin of the LZ, Fermi-LAT, and AMS-02 Excesses and Paleo-Detector Prospects
Abstract
We investigate the 248~keV nuclear recoil excess reported by LUX-ZEPLIN (LZ) in a leptophobic inelastic dark matter framework, in which the mass splitting naturally suppresses low-energy recoils. We find two viable branches, including the endothermic solution with a high dark matter mass mχ≳400~GeV and the exothermic one with a mass of tens GeV. Remarkably, the exothermic dark matter scenario with mχ∼55~GeV can simultaneously account for the LZ excess, the Galactic Center GeV gamma-ray excess, and the AMS-02 antiproton excess. The favored annihilation cross-section is slightly below the one required for the observed relic abundance, resulting in an overabundant relic in the minimal setup. An additional neutrino-portal mediator can provide the required depletion while leaving the gamma-ray and antiproton signals essentially unchanged. We further show that paleo-detectors provide a powerful probe of the inelastic interpretation, requiring exposures of ∼10 and ∼100~mg Gyr for the endothermic and exothermic scenarios, respectively.
Related
- LIGO A♯: Detector Design and Science Prospects Beyond A+
- Direct detection constraints on EFT operators for inelastic dark matter
- Inelastic Signatures of Electroweak Dark Matter
- Solar Neutrino Constraints on Inelastic Dark Matter Scattering in Light of Recent LUX-ZEPLIN Observations
- Core-collapse universality for inelastic self-interacting dark matter halos
BibTeX
@misc{yang2026common,
title = {{A Common $\sim$55 GeV Inelastic Dark Matter Origin of the LZ, Fermi-LAT, and AMS-02 Excesses and Paleo-Detector Prospects}},
author = {Meiwen Yang and Quan-feng Wu and Kai-Kai Duan and Zi-Qing Xia and Yue-Lin Sming Tsai and Yi-Zhong Fan},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.06640},
eprint = {2609.06640},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.06640},
}
RIS
TY - UNPB
TI - A Common ∼55 GeV Inelastic Dark Matter Origin of the LZ, Fermi-LAT, and AMS-02 Excesses and Paleo-Detector Prospects
AU - Meiwen Yang
AU - Quan-feng Wu
AU - Kai-Kai Duan
AU - Zi-Qing Xia
AU - Yue-Lin Sming Tsai
AU - Yi-Zhong Fan
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2609.06640
UR - https://arxiv.org/abs/2609.06640
AB - We investigate the 248~keV nuclear recoil excess reported by LUX-ZEPLIN (LZ) in a leptophobic inelastic dark matter framework, in which the mass splitting naturally suppresses low-energy recoils. We find two viable branches, including the endothermic solution with a high dark matter mass m_χ≳400~GeV and the exothermic one with a mass of tens GeV. Remarkably, the exothermic dark matter scenario with m_χ∼55~GeV can simultaneously account for the LZ excess, the Galactic Center GeV gamma-ray excess, and the AMS-02 antiproton excess. The favored annihilation cross-section is slightly below the one required for the observed relic abundance, resulting in an overabundant relic in the minimal setup. An additional neutrino-portal mediator can provide the required depletion while leaving the gamma-ray and antiproton signals essentially unchanged. We further show that paleo-detectors provide a powerful probe of the inelastic interpretation, requiring exposures of ∼10 and ∼100~mg Gyr for the endothermic and exothermic scenarios, respectively.
ER -